BOSS HM-3 mods - the Swedish Army Knife

Tetanus

Well-Known Member
#1
as you know, i love the HM-3 pedal. you can read my previous post HERE
in a nutshell:
It is between the HM-2 heavy metal and MT-2 metal zone.
This pedal is awesome as a booster on the dist/od channel of a gainy amp.
On its own as a distortion pedal it sounds shit....
The Dist. could be at zero, but even then adds a bit of that grit, which reminds me to the famous Swedish tone (HM-2). Even a higher Dist. setting it is not as fuzzy; more articulate, cut through the mix better etc.

And since it is almost like a booster on a minimum Dist. setting, i decided to make a few mods.



t
he controls:
Switch #1: to choose between Booster and Distortion. In Booster mode there is no clipping diodes in the circuit. None. If you turn up the Dist. in this mode, the pedal start to become an OpAmp/IC driven fuzz, like the BigMuff Billy Corgan used....
Switch #2: to choose different Diodes. Stock or Red LEDs. Stock is more compressed = less volume, more highs and more lows. LEDs are more open and mid focused, but still deliver plenty of distortion.
Stacked potentiometers:
Volume // Dist
Bass // and it's Frequency
Mids // and it's Frequency
Treble // Tightness control.

further details about the tone controls:
all 3 tone controls (Bass, Mids, Treble) are active, means they are either cut or boost their frequencies. At 12 O'clock they are not affecting the signal.
The frequency controls change the Q value as well. Lower setting got narrower Q, while higher frequency setting got wider Q. And this is great, because as a general rule: we should Cut with a narrow Q, and Boost with a wider Q.

Bass frequencies: between around 80 - 200 Hz.
again, narrow Q at lower freq. settings, wider at higher settings. This could work well in most cases, as if your overall tone got too much bass and you would like to filter out some (to not interfere with the bass guitar and/or kick drums for example), you can find the right Frequency and cut/filter it out without sacrificing the low end of your tone. If you would like to add more bass to your signal, then the wider Q comes handy...

Mid Frequencies: between 300 - 3k Hz
same as above with the Freq./Q relationship.

Treble: Originally the Mids and Highs were adjusted with the same "high" control and the frequency of these two were really close to each other. The highs were originally around 4-5kHz. It was more like in a high-mid/presence territory.
I shifted this to around 7kHz. This way all 3 controls working in their own range. The Q is set more narrow than wide, so it won't add any unnecessary annoying high frequencies, but add the highs which are necessary to the guitar tone.

Tightness: this is basically a high pass filter, you can dial the cut off frequency between around 50 - 220 Hz.
This is at the end of the signal chain. You can control the overall Bass at the end of the signal chain as well with it. It might sounds unnecessary at first, but believe me, this could come handy.
On minimum setting it does not affect the tone as anything below 50 Hz would not needed for guitar. But if you dial in your tone with lots of bass, you can tidy up the overall tone...


I am pleased with this pedal.
I just need a face place to be designed now. :)
If you have a good idea how to do it, please share. Thanks.
 
Last edited:

johnniegoat

Stop, don’t, come back.
#3
@Tetanus
if you have a photobucket account, upload the pics there

then copy and paste the URL link here - it will then show the pics

edit - its the IMG url
 
Last edited:

Tetanus

Well-Known Member
#4
I tried to upload it from my PC. Error: file is too big. 81kb !!!

Tried to link it from my DropBox account.

Tried several photo uploader sites (not Photobucket though)


No luck.


Sent from my iPhone using Tapatalk
 

everfreetree

I... I like trees.
#5
I tried to upload it from my PC. Error: file is too big. 81kb !!!

Tried to link it from my DropBox account.

Tried several photo uploader sites (not Photobucket though)


No luck.


Sent from my iPhone using Tapatalk
I usually use Imgur, then just copy the "direct link" from the image, and click the little image icon on the new post, then paste it there.
If that doesn't work, I have no idea.

Test image:
 

Tetanus

Well-Known Member
#9
fuck this shit... i hate that this forum is always difficult for me... i never had such problem on other forums..

certificates, flash etc. always causing some shit...
 

everfreetree

I... I like trees.
#11
nope... even imgur don't work for me...

I think the link you used was the Imgur link, but not the Direct link. Try opening the image in a new tab (right click it and find that option) and then copying the link that has the ".jpg" in it.
If that doesn't work, it's something odd about how your end interacts with the forums, so sadly, we can't do jack x_x.



On-topic with the original post though, that looks pretty dang awesome.
Little toggles AND concentric knobs. Neat.
 

Tetanus

Well-Known Member
#12
I think the link you used was the Imgur link, but not the Direct link. Try opening the image in a new tab (right click it and find that option) and then copying the link that has the ".jpg" in it.
If that doesn't work, it's something odd about how your end interacts with the forums, so sadly, we can't do jack x_x.

On-topic with the original post though, that looks pretty dang awesome.
Little toggles AND concentric knobs. Neat.
Thanks for the photo and for the comment as well. :)
I tried to upload from my computer, and it didn't work either... tried with mozilla and Chrome too...
Tried the direct link, the embed etc none worked...
 

Tetanus

Well-Known Member
#14
i am about to test if I could make a custom faceplate as well.
I got a design, nothing fancy, just the controls labelled up.
Seen a video of using some vinyl sticker backing paper and laser printer, which could give me good enough result.

I already sanded and spray painted the original faceplate. Black, of course. 2 layers.
Then I need to print out the design, apply a thin coat of lacquer, transfer the design and then seal and protect it with 2-3 layers of thin lacquer.






P.S.: In the drawing app and even printed the quality is much much better... but it will do for the show-off purposes :)
 

Tetanus

Well-Known Member
#17
ok, the first try of transfer did not go well.. :(



the orange colour disappeared completely. Probably the Lacquer reacted with the print....
Also it is a smudge at the bottom section..
I think i will rather just print it on a clear transparent vinyl and give it a clear coat lacquer layer as a finish to protect it...
 

Tetanus

Well-Known Member
#18
Another few try and errors later:
The black praypaint which i used as a base (background ) completely ruins the orange colour. Ot doesn't matter if i transfer the paint or even if i use it as a label on top of it... :(
The orange ended up to be dark green and barely visible. Which i don't understand as i even printed it on a transparent vinyl so it was not even in contact with the black paint..
At the end i sanded back the plate to bare aluminium, tried to polish it somewhat and applied a "sticker" on top.

It is not perfect, the orange colour is not matching the original shade... well, it is not really far either...











Sent from my iPhone using Tapatalk
 

Tetanus

Well-Known Member
#19
as another experiment, I attached a white sheet of paper as a "background" behind the vinyl sticker, so the orange will stood up better.
And since i made a few scratches very easily on the previous vinyl i decided to add a clear layer on top of it...
Unfortunately the circular cut outs looking untidy as it was really difficult to cut the 3-4mm diameter into multiple layers (aluminium sheet, white paper, print, clear layer).
The clear layer isn't stuck properly and evenly onto the printed layer... But I was afraid to use a clear lacquer spray layer...
anyway, it think i will leave it as it is. The pedal is working, aesthetically is not as i wanted but hey-ho...



 

Tetanus

Well-Known Member
#20
since then i had another project and it occurred to me to revisit this pedal as well.
I love how it turned out sound wise. But the labels are so temporary... I got some water decals at home and will give it a try to make this look a bit more professional.I will have a few days off during the holidays and I really would do this. :)
 
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